Using valid TLS Cert does not work. Browser reports "cert is not standards compliant"

[meenie]

I've created a secret in my K8s environment in Google GKE setting the ca.crt and ca.key as requested in the docs. But when trying to load the URL in the browser, Chrome reports back that the certificate is "not standards compliant". And if I try to use FireFox, it returns an error of: SEC_ERROR_INADEQUATE_KEY_USAGE. Could the issue be that I'm trying to use a wildcard certificate? I've tried this with two different certs from two different companies and I got the same result both times. Screenshot below:

[maierlars]

SEC_ERROR_INADEQUATE_KEY_USAGE indicates that you used a certificate for signing that is not allowed to do that. Thus the chain of trust is broken and clients rightfully decline the certificate.